JP4960117B2 - Decorative key sheet for pushbutton switches - Google Patents

Description

  The present invention relates to a decorative key sheet for a pushbutton switch used for an operation unit of an electronic device such as a portable information terminal, a PDA, an AV device, various remote controllers, and various keyboards.

  Electronic devices such as portable information terminals and PDAs are becoming smaller and thinner, and input components such as key sheets used for these devices are required to be thin enough to realize a thinner electronic device. On the other hand, the key sheet is decorated with various decorations that enhance the design value in order to differentiate the products and express a high-class feeling. One of the decorations is a hairline pattern having a metallic luster. From such a background, a thin key sheet having a hairline pattern is embodied by the following technique.

  For example, if a technique using a metal plate such as an aluminum plate or a stainless steel plate as described in JP-A-2002-008476 (Patent Document 1) or JP-A-2006-156333 (Patent Document 2) is used, A key sheet with a hairline pattern having a metallic luster by applying a fine uneven pattern to the surface of the metal plate can be realized.

  Further, as disclosed in JP-A-6-305063 (Patent Document 3) and JP-A-2005-111865 (Patent Document 4), a fine uneven hairline pattern is provided on the surface of the resin sheet, If the surface is covered with a metal thin film layer or a metallic paint film, a hairline pattern key sheet having a metallic luster can be realized.

Furthermore, by using the technique described in Japanese Patent Application Laid-Open No. 2003-109450 (Patent Document 5) and Japanese Patent Application Laid-Open No. 2006-185699 (Patent Document 6), a fine uneven hairline pattern is formed on the back surface of the transparent member. And if a metal thin film layer and a metal-like coating film are provided in the hairline pattern surface, the keyline of the hairline pattern which has metal luster is realizable.
JP 2002-008476 A JP 2006-156333 A JP-A-6-305063 JP 2005-111865 A JP 2003-109450 A JP 2006-185699 A

  However, although the technique using the metal plate described in Patent Document 1 and Patent Document 2 has high durability of the uneven pattern and can maintain the metallic luster, the tip of the metal plate is used for parts that touch the hand like a key sheet. There is a risk that the operator may be injured at the portion or the edge portion, and it is necessary to smoothly process the tip portion or the edge portion by polishing or etching, or to coat it with a polymer material. For this reason, the manufacturing process is troublesome and the cost is increased.

  Moreover, although the technique which decorates the surface of the resin described in patent document 3 and patent document 4 can improve safety compared with a metal plate, a metal thin film layer and a metal-tone coating film are worn by contact with a hand etc. Since it is easy to peel off from the resin, it is difficult to maintain a high-class feeling. Moreover, when a metal thin film layer or a metallic coating film is put on a fine uneven surface, the recessed portion is buried and the hairline pattern becomes inconspicuous, making it difficult to exhibit the design value.

  Furthermore, although the technique for decorating the back surface of the transparent member described in Patent Document 5 and Patent Document 6 can prevent wear and peeling of the metal thin film layer and the metallic tone coating film, the fine uneven hairline seen through the transparent member The pattern is difficult to see. Therefore, if the surface of the transparent member is made smooth in order to improve the visibility, the surface of the transparent member is easily soiled by contact with a hand or the like, and the high-class feeling is impaired.

  The present invention has been made against the background of the prior art as described above. That is, an object of the present invention is to provide a decorative key sheet for a pushbutton switch that has high visibility, is excellent in design, and maintains a high-class feeling. Another object of the present invention is to provide a decorative key sheet for a push button switch that allows an operator to safely perform an input operation. Another object of the present invention is to provide a thin decorative key sheet for a pushbutton switch.

  In order to achieve the above object, the present invention is configured as follows. That is, the present invention provides a push button having a fine uneven pattern on the operation surface side of the translucent sheet, and a decorative auxiliary layer that enhances the visibility of the fine uneven pattern on the side opposite to the operation surface of the translucent sheet. Provides decorative key sheets for switches.

  In this invention, since it has a fine unevenness | corrugation pattern in the operation surface side of a translucent sheet | seat, the design of a fine unevenness | corrugation pattern can be visually recognized clearly. Moreover, it is difficult for fingerprints or sebum of the fingers of the operator to adhere to the concavo-convex surface portion constituting the fine concavo-convex pattern, and deterioration in quality due to dirt can be suppressed. Furthermore, since there is a decorative auxiliary layer on the side opposite to the operation surface (back side) of the translucent sheet, the operator's hand does not come into contact with the decorative auxiliary layer, and the decorative auxiliary layer can be prevented from being worn or peeled off. it can. Moreover, since the translucent sheet is translucent and has a decorative auxiliary layer on the back side of the translucent sheet, the light passing through the fine uneven pattern is reflected by the decorative auxiliary layer and further passes through the fine uneven pattern. Reach the eyes. Therefore, the color, gloss, and texture of the decorative auxiliary layer are emphasized through the fine uneven pattern, so that the color, gloss, and texture of the decorative auxiliary layer can be fully seen and the fine uneven pattern becomes easy to see, We can realize a novel design with a feeling.

  It is possible to provide a decorative key sheet for a pushbutton switch that includes a translucent resin layer on the operation surface side surface of the translucent sheet and has the fine uneven pattern on the outer surface of the resin layer. Since the translucent resin layer is provided on the surface of the translucent sheet on the operation surface side and the outer surface of the resin layer has the fine concavo-convex pattern, the design of the fine concavo-convex pattern can be clearly recognized. . Furthermore, fingerprints and sebum on the operator's fingers are difficult to adhere, and deterioration in quality due to dirt can be suppressed. A decorative key sheet for a pushbutton switch that is excellent in design and maintains a high-class feeling can be realized. In addition, the resin layer can be made hard, and the translucent sheet positioned inside the resin layer can be made of a soft resin, thereby expanding the range of material selection.

  A decorative key sheet for a pushbutton switch having a fine concavo-convex pattern on the outer surface on the operation surface side of the translucent sheet can be obtained. Since the decorative key sheet for a push button switch having a fine uneven pattern on the outer surface on the operation surface side of the translucent sheet is used, the design of the fine uneven pattern can be clearly recognized. Furthermore, fingerprints and sebum on the operator's fingers are difficult to adhere, and deterioration in quality due to dirt can be suppressed. A decorative key sheet for a pushbutton switch that is excellent in design and maintains a high-class feeling can be realized. Further, the above-described translucent resin layer can be omitted. Therefore, the decorative key sheet for the push button switch can be easily manufactured, and the manufacturing cost can be reduced.

  The decoration auxiliary layer can be a light reflecting layer having a metallic luster. Because the decoration auxiliary layer is a light reflective layer with a metallic luster, it is possible to realize a metal-like hairline pattern with high visibility and design, coupled with the diffusion of light that occurs on the uneven surface of the fine uneven pattern it can.

  Moreover, this invention can be used as the decorating key sheet | seat for pushbutton switches provided with the following more restrictive structures. The first is an operation plate in which the translucent sheet is provided with a partition groove that forms a pressing operation piece that can be pressed and displaced, and bulges toward the partition groove from the side opposite to the operation surface of the operation plate. It is a decorative key sheet for pushbutton switches provided with a film sheet provided with projections to perform.

  Since the fine concavo-convex pattern is provided on the outer surface on the operation surface side of the operation plate, the design of the fine concavo-convex pattern can be clearly recognized. Furthermore, fingerprints and sebum of the operator's fingers are difficult to adhere to the uneven surface portion constituting the fine uneven pattern, and deterioration in quality due to dirt can be suppressed. And since it has a decorative auxiliary layer that enhances the visibility of the fine concavo-convex pattern on the side opposite to the operating surface (back side) of the operating plate, the operator's hand does not contact the decorative auxiliary layer, Peeling can be prevented. Furthermore, since the operation panel is translucent, the color, luster, texture, etc. of the decoration auxiliary layer on the back surface can be fully seen through the fine concavo-convex pattern, and a high-class and innovative design can be realized. . In addition to these advantages, it has a film sheet with protrusions that bulge from the back of the operation plate toward the partition groove, so that the film sheet prevents the nails and fingertips from entering deep into the groove of the partition groove. It can prevent nails and fingertips from being damaged. Moreover, it can be set as a thin decoration key sheet | seat by being comprised with an operation board and a film sheet.

  With respect to the first decorative key sheet for pushbutton switches, the protrusion can protrude from the outer surface of the operation plate. Therefore, the position of the partition groove can be confirmed by the protrusion shape, and the area of the pressing operation piece can be easily identified by tactile sensation. Therefore, erroneous input can be prevented. In addition, this is a decorative key sheet for a pushbutton switch that can eliminate the entry of nails and fingertips into the partition groove and can be operated safely by the operator.

  The first decorative key sheet for pushbutton switches may further include an elastic sheet made of a rubber-like elastic body on the back surface of the film sheet. The elastic sheet can have a restoring force when the pressing operation piece is pressed.

  In the first decorative key sheet for pushbutton switches, the inside of the protrusion can be a solid part made of a rubber-like elastic body. Since the solid portion is used, even when the projection is pressed with a fingertip during the pressing operation, the solid portion repels from the inside of the projection and the depression of the projection can be prevented. Further, since both the elastic sheet and the solid part filling the inside of the protrusion are rubber-like elastic bodies, the elastic sheet and the solid part can be formed simultaneously. Therefore, manufacture is easy and integration with the operation plate can be easily realized.

  The first decorative key sheet for a pushbutton switch may be provided with a pressing operation piece that is formed into an annular partition groove and partitioned by the annular partition groove. Since such a pressing operation piece is provided, a key sheet with a novel design can be realized. Further, since the pressing load for deforming the protrusion located in the groove of the partition groove is smaller than the pressing load for bending the operation plate, the pressing operation piece partitioned by the annular partition groove is surrounded by the partition groove in, for example, three directions. The pressing load can be reduced as compared with other pressing operation pieces.

  The first decorative key sheet for a push button switch may have a gap between the protrusion and the side surface of the partition groove. If there is a gap, the protrusion and the pressing operation piece are separated from each other, so that the deformation of the protrusion can be reduced when the pressing operation piece is pressed. Therefore, the load for deforming the protrusion is reduced, and the pressing load of the pressing operation piece can be reduced.

  Regarding the first decorative key sheet for pushbutton switches, the one provided with an elastic sheet may have a recess between adjacent pressing operation pieces. Since the elastic sheet between the adjacent pressing operation pieces has the recess, the elastic sheet between the pressing operation pieces can be formed thin. Therefore, the elastic sheet can be easily deformed when the pressing operation piece is pressed, and the pressing load of the pressing operation piece can be reduced.

  A second decorative key sheet for pushbutton switches having a restrictive structure is a frame sheet that has a key top and a base sheet made of a resin film, and the translucent sheet is arranged on the base sheet side by side with the key top. A decorative key sheet for a pushbutton switch, which is formed as a printed layer and includes a printed adhesive layer formed of a cured body that is in contact with the key top, the frame sheet, or the base sheet in a softened or molten state.

  Since the operation surface side of the frame sheet has a fine concavo-convex pattern, the design of the fine concavo-convex pattern can be clearly recognized. Furthermore, fingerprints and sebum of the operator's fingers are difficult to adhere to the uneven surface portion constituting the fine uneven pattern, and deterioration in quality due to dirt can be suppressed. And since it has a decorative auxiliary layer on the opposite side (back side) to the operation side of the frame sheet, it can prevent the decorative auxiliary layer from being worn or peeled off due to contact with the operator's hand Can do. Furthermore, since the frame sheet is translucent, the color, luster, texture, etc. of the decoration auxiliary layer on the back surface can be fully seen through the fine concavo-convex pattern, and a high-class and innovative design can be realized. . In addition to these advantages, a base sheet made of a resin film, a key top disposed on the base sheet, and a hardened body formed as a printing layer and in contact with the key top, frame sheet, or base sheet in a softened or molten state. Since a printing adhesive layer is provided, a thin decorative key sheet can be obtained. And it can be set as the decorating key sheet | seat which has the printing adhesive layer which controlled the adhering position and application | coating thickness of a key top and a base sheet with high precision. In other words, compared to the conventional case where, for example, the adhesive is dropped on the bottom surface of the key top, there is no variation in the position and area of the adhesive layer, and the key top is firmly fixed and is thin and difficult to fall off. It can be a key sheet. In particular, since it has a frame sheet between the key tops, it is a thin decorative key sheet in which a toe does not easily enter between the key top and the base sheet, and the key top does not easily come off.

  Regarding the second decorative key sheet for pushbutton switches, the printing adhesive layer may form a side surface substantially flush with the side surface of the key top between the base sheet and the key top. Since the printed adhesive layer forms a side surface that is substantially flush with the side surface of the key top between the base sheet and the key top, there is no gap at the boundary between the key top and the base sheet, and the key top becomes the base sheet. It can be firmly fixed. Therefore, it is difficult for the toe to get caught, and the key top can be prevented from falling off. Note that “substantially flush” means that the side surface of the printed adhesive layer is in an uneven state of ± 0.5 mm or less with respect to the side surface of the key top.

  With respect to the decorative key sheet for the second pushbutton switch, the printing adhesive layer may be formed on the bottom surface of the frame sheet excluding the outer edge side adjacent to the key top. Since the printing adhesive layer is formed on the bottom surface of the frame sheet excluding the outer edge side adjacent to the key top, there is a void without the printing adhesive layer on the outer edge side of the frame sheet with the key top. Is a non-restraint region when the key top is pressed. Therefore, it is possible to perform a reliable pressing operation of the key top. That is, since there is an unconstrained area around the key top, in the base sheet that supports the key top, an area that is not constrained by the printing adhesive layer spreads only in the gap portion, and the base sheet is easily bent. For this reason, it is possible to obtain a decorative key sheet which can take a long key stroke and can perform an accurate key input operation even if it is thin.

  According to the decorative key sheet for a pushbutton switch of the present invention, the design of the fine uneven pattern can be clearly recognized. Furthermore, fingerprints and sebum on the operator's fingers are difficult to adhere, and deterioration in quality due to dirt can be suppressed. A decorative key sheet for a pushbutton switch that is excellent in design and maintains a high-class feeling can be realized.

  Moreover, according to the decorative key sheet for pushbutton switches of the present invention, it is a decorative keysheet for pushbutton switches that allows the operator to perform an input operation safely and reliably. Furthermore, according to the decorative key sheet for a push button switch of the present invention, it is a thin decorative key sheet for a push button switch that does not cause problems such as dropping off of the key top.

  Hereinafter, embodiments of a decorative key sheet for pushbutton switches (hereinafter abbreviated as “decorative key sheet”) of the present invention will be described with reference to the drawings. In addition, duplication description is abbreviate | omitted about the member, material, structure, manufacturing method, and effect which are common in each embodiment.

1st Embodiment [FIGS. 1-3] : The decorating key sheet | seat 1 of 1st Embodiment is shown in FIGS. 1-3. FIG. 1 is an external view of a mobile phone 2 including a decorative key sheet 1, FIG. 2 is a plan view of the decorative key sheet 1, and FIG. 3 is a cross-sectional view of the decorative key sheet 1. The decorative key sheet 1 of the first embodiment is used on the mobile phone 2 shown in FIG. 1 so as to be exposed from the operation opening 2a without a partition rail. An operation plate 3 as a “translucent sheet”, a film sheet 4, and an elastic sheet 5 are provided.

  The operation plate 3 is a member that functions as an operation plate of a push button switch, and is also a member corresponding to a key top of a type that performs an input operation by pressing the key top. The operation plate 3 is a single plate made of resin. The single plate is provided with a partition groove 3a penetrating the wall in a square wave shape, and a portion partitioned in a tongue shape by the partition groove 3a is provided. It becomes the pressing operation piece 3b and can be deformed during the input operation. In FIG. 1 and FIG. 2, the shape of the partition groove 3a is such that, for example, in the pressing operation piece 3b in which the display unit 6 representing the symbol “*” can be visually recognized, the display unit 6 that is partitioned vertically in the drawing and represents the number “0” The visually recognized pressing operation piece 3b is formed in a square wave shape so as to be partitioned upward.

  A transparent resin layer 7 is provided on the surface 3c on the operation surface side of the operation plate 3, and the outer surface of the resin layer 7, that is, the exposed external surface is provided with a fine uneven pattern to form an uneven surface portion 7a. Yes. The interval between the concave portions in the uneven surface portion 7a is preferably 10 μm to 500 μm, the depth of the concave portion is preferably 1 μm to 200 μm, and the depth of the concave portion is more preferably 5 μm to 30 μm. If the distance between the recesses is less than 10 μm, it is difficult to manufacture. If the depth of the recess is less than 1 μm, the fine uneven pattern becomes inconspicuous, and if the depth exceeds 200 μm, it becomes difficult to manufacture. A so-called hairline-like design can be visually recognized by such an uneven surface portion 7a.

  On the side opposite to the operation surface of the operation plate 3, that is, on the back surface 3d of the operation plate 3, a light reflecting layer 8 as a “decoration auxiliary layer” is provided. The light reflecting layer 8 is combined with the concavo-convex surface portion 7a to give the fine concavo-convex pattern a color tone and gloss, and to enhance the texture of the fine concavo-convex pattern. A more luxurious design can be obtained. Between the light reflecting layer 8 and the back surface 3d of the pressing operation piece 3b, a display unit 6 such as symbols and numerals is printed.

  The film sheet 4 is a member that enters the partition groove 3 a formed in the operation plate 3 from the back side of the operation plate 3 and closes the partition groove 3 a. That is, the film sheet 4 is formed from a single sheet, but is fixed to the back surface 3d of the operation plate 3 with an adhesive layer (not shown), while the inside of the partition groove 3a is directed from the back surface 3d side to the front surface 3c side. A protrusion 4a that bulges out is formed and closes the partition groove 3a. Further, the tip of the protrusion 4 a protrudes from the surface 3 c of the operation plate 3.

  The elastic sheet 5 is positioned on the back surface of the film sheet 4 to form a base portion 5b, impart rubber-like elasticity to the entire decorative key sheet 1, and constitute a protruding portion 5a and a pusher portion 5c. The protruding portion 5a is formed as a “solid portion” so as to fill the space of the protrusion 4a in the film sheet 4, and the base portion 5b integrally connects the plurality of protruding portions 5a. The base portion 5b is provided with a pusher portion 5c for pressing a contact switch (not shown) for each pressing operation piece 3b.

  Here, the material of each constituent member of the decorative key sheet 1 will be described.

  The material of the operation plate 3 is preferably resin or glass, and among these, the resin material can be a light-transmitting and highly rigid hard resin, and is preferably transparent. Examples thereof include polypropylene resin, polystyrene resin, polycarbonate resin, polyester resin, acrylic resin, polyamide resin, and polyimide resin. The wall thickness of the operation plate 3 can be set to 50 μm to 2000 μm. Further, a soft resin that bends when one end is held can also be used. This is because, if the film sheet 4 has regularity, the operation plate 3 laminated and integrated with the film sheet 4 does not have to be hard. The softness of the decorative key sheet 1 can be increased by using a soft resin.

  The material of the resin layer 7 provided on the surface 3c of the operation plate 3 is a light-transmitting hard resin, and is particularly preferably transparent as in the present embodiment. In addition, if a material having a surface hardness of H or higher as defined in JIS K 5600-5-4: 1999 is used, scratch resistance can be improved. For example, an acrylic resin, a urethane resin, an epoxy resin, a vinyl acetate resin, etc. are mentioned. In addition, it is preferable to use a thermosetting resin and a photocurable resin from the viewpoint of production described later. Since the resin layer 7 is made of a hard resin having excellent scratch resistance, the fine uneven pattern is not damaged even if the outer surface has a fine uneven pattern. Moreover, since the resin layer 7 consists of hard resin, the operation board 3 located in the inside can be formed with soft resin.

  The material of the “decoration auxiliary layer” provided on the back surface 3d of the operation plate 3 is preferably a material that can express a design that enhances the visibility of the fine concavo-convex pattern provided on the front surface 3c side of the operation plate 3. That is, it is possible to use a material that enhances visibility such as light refraction, scattering, and interference caused by the fine concavo-convex pattern. For example, a material that imparts a metallic luster such as a metal thin film, or a material that imparts a color tone such as a metallic or blackish polymer coating film is preferable. Examples of metal thin films include metal thin films made of aluminum, chromium, copper, germanium, gold, indium, iron, lead, magnesium, nickel, palladium, platinum, silver, tin, titanium, zinc, etc. It is preferable to use aluminum, silver, indium, magnesium, tin, or the like that is easy to handle. The polymer coating is preferably a urethane resin, acrylic resin, ester resin, vinyl acetate resin, vinyl chloride resin, epoxy resin or the like containing a color pigment, a pearl pigment, a metal powder, or the like.

  The material for forming the film sheet 4 may be a material such as a resin film made of a thermoplastic resin that has both flexibility and wear resistance and can form a protrusion shape. For example, polyolefin resin, polyester resin, polyurethane resin, polyamide resin, soft polyvinyl chloride resin and the like can be mentioned. If the thickness of the film sheet 4 is 10 μm to 200 μm, protrusions can be formed without being damaged. However, the selection range of the material used for the film sheet 4 can be changed in consideration of the material used for the operation plate 3. When the operation plate 3 is a hard resin having a formability that does not bend when one end is held, a soft resin that does not have such a formability can be used. Is a soft resin that does not have such a regularity, the film sheet 4 needs to be made of a hard resin that has a regularity.

  The elastic sheet 5 is made of a thin rubber-like elastic body, and is preferably a thermosetting elastomer or a thermoplastic elastomer having good rebound. For example, silicone rubber, isoprene rubber, ethylene propylene rubber, butadiene rubber, chloroprene rubber, natural rubber, styrene thermoplastic elastomer, ester thermoplastic elastomer, urethane thermoplastic elastomer, olefin thermoplastic elastomer, amide thermoplastic elastomer Butadiene-based thermoplastic elastomer, ethylene-vinyl acetate-based thermoplastic elastomer, fluorine-based thermoplastic elastomer, isoprene-based thermoplastic elastomer, chlorinated polyethylene-based thermoplastic elastomer, and the like. Further, silicone rubber is preferable in view of the low temperature dependence of these rubber-like elastic bodies, and styrene-based thermoplastic elastomers and ester-based thermoplastic elastomers are preferable in consideration of durability.

  An example of a method for manufacturing the decorative key sheet 1 will be described. First, the operation plate 3 made of a transparent resin is formed by injection molding. At this time, the partition groove 3a penetrating the wall thickness is formed by the cavity of the injection mold. The operation surface side of the operation plate 3 is opposed to a mold having a fine concavo-convex pattern, a liquid photocurable resin is injected between the operation plate 3 and the mold, and then light is transmitted from the operation plate 3 side. When the photocurable resin is cured by irradiation to remove the mold, the operation plate 3 having the resin layer 7 on which the fine concavo-convex pattern is formed on the surface 3c on the operation surface side can be obtained. After the display portion 6 is printed on the back surface 3d of the operation plate 3, a metal thin film is attached by dry plating to form the light reflecting layer 8. Further, an adhesive layer made of a hot melt adhesive is applied to the light reflecting layer 8. Then, the resin layer 7 on the surface 3c of the operation plate 3 is inserted into a mold for forming the film sheet 4 so as to be in contact with the mold surface, and then the film sheet 4 is placed on the back surface 3d side of the operation plate 3. The mold is closed and the film sheet 4 is heated and embossed. At this time, the film sheet 4 is formed with a protrusion 4a that is pushed and extended by the protrusion of the mold in the groove of the partition groove 3a, and the back surface 3d of the operation plate 3 and the film sheet 4 are fixed. Finally, after inserting the resin layer 7 on the surface 3c of the operation plate 3 into the mold for molding the elastic sheet 5 so as to be in contact with the mold surface, a rubber-like elastic body is placed on the film sheet 4 and the mold is placed. The mold is closed and the elastic sheet 5 is formed by compression molding. At this time, the protrusion 5a is formed in the protrusion 4a. Thereby, the decorative key sheet 1 can be obtained.

  As a method for forming a fine concavo-convex pattern, a metal plate or an embossing roll having a concavo-convex pattern on the surface is used instead of a mold, the metal plate or the embossing roll and the operation plate 3 are opposed to each other, and a liquid is formed between them. It can also be obtained by injecting and curing a thermosetting or photo-curing resin.

  The effect of the decoration key sheet 1 of this embodiment is demonstrated. According to the decorative key sheet 1, in addition to being thin, which includes the operation plate 3, the film sheet 4, and the elastic sheet 5, there is a fine uneven pattern on the surface 3 c side of the operation plate 3. The design can be clearly seen. In addition, fingerprints and sebum of the operator's fingers are difficult to adhere to the uneven surface portion 7a of the resin layer 7 constituting the fine uneven pattern, and deterioration in quality due to dirt can be suppressed. Furthermore, since the light reflecting layer 8 that enhances the visibility of the fine concavo-convex pattern is provided on the back surface 3d of the operation plate 3, it is possible to prevent the light reflecting layer 8 from being worn or peeled off by contact with the operator's hand. Further, since the operation plate 3 is transparent, the metallic luster of the light reflecting layer 8 on the back surface 3d side can be sufficiently visually recognized through the fine concavo-convex pattern, and a high-class and innovative design can be realized.

  Since the fine concavo-convex pattern is formed on the outer surface of the resin layer 7, even if the operator touches the concavo-convex surface portion 7a of the fine concavo-convex pattern by hand, it can be made difficult to be injured, and the operator can safely perform an input operation. be able to.

  Since the light reflection layer 8 having a metallic luster is provided as a “decorative auxiliary layer”, the fine uneven pattern becomes easy to see, and the metal-like hairline pattern is realized in combination with the light diffusion occurring on the uneven surface portion 7a of the fine uneven pattern. can do.

  Since the protrusion 4a of the film sheet 4 protrudes from the surface 3c of the operation plate 3, the position of the partition groove 3a can be confirmed by the protrusion shape, and the area of the pressing operation piece 3b can be easily identified by tactile sensation. Therefore, erroneous input can be prevented. Further, it is possible to eliminate the entry of nails and fingertips into the partition groove 3a.

  Since the elastic sheet 5 made of a rubber-like elastic body is provided on the back surface of the film sheet 4, the elastic sheet 5 can have a restoring force when the pressing operation piece 3b is pressed.

  Since the inside of the protrusion 4a of the film sheet 4 is a “solid portion” of the protruding portion 5a made of a rubber-like elastic body, the protruding portion 5a remains inside the protrusion 4a even if the protrusion 4a is pressed with a fingertip during the pressing operation. Therefore, the dent of the protrusion 4a can be prevented. In addition, since the elastic sheet 5 and the protruding portion 5a can be formed at the same time, manufacturing is easy and integration with the operation plate 3 can be easily realized.

The partition grooves 3a of the operation plate 3 is an annular, because with a depressing operation member defined depending on the dividing grooves of the annular, can be realized decorative key sheet 1 of a novel design. The pressing load deforming the protrusions 4a situated in the dividing grooves is smaller than the depression load bending the operation plate 3, the pressing operation member defined depending on the annular partition groove, for example a three-way partition groove The pressing load can be reduced as compared with the other pressing operation pieces 3b surrounded by 3a.

First Modification of First Embodiment [FIG. 4] : In the decorative key sheet 1, the example in which the display unit 6 is printed on the back surface 3d of the operation panel 3 is shown. However, as shown in FIG. In the decorative key sheet 9 of the example, the operation plate 10 can be formed with a recess 10a representing a display unit. Even in this way, the operator can visually recognize the display unit. In addition, a display part can also be used as the through-hole which penetrates the thickness of an operation board.

Second Modified Example of First Embodiment [FIG. 5] : In the decorative key sheet 1, the example in which the protrusion 4a of the film sheet 4 protrudes from the surface 3c of the operation plate 3 is shown, but as shown in FIG. In the decorative key sheet 11 of the second modification, the tip of the projection 12a of the film sheet 12 and the surface 3c of the operation plate 3 can be flush with each other. In this way, the shearing direction force by the fingertip or the like is not applied to the protrusion 12a, and it is difficult to deform the protrusion 12a by the fingertip or the like. The tip of the protrusion can be slightly recessed from the surface 3c of the operation plate 3. In this way, as in the second modified example, a shearing direction force from the fingertip or the like is not applied to the protrusion, and the protrusion due to the fingertip or the like can be prevented from being deformed. Further, since the recess of the partition groove 3a is formed to be small, the area of the pressing operation piece 3b can be easily identified by the tactile sensation of the fingertip, and not only can an erroneous input be prevented, but also a nail or fingertip compared to the case where there is no protrusion Can be reduced.

Third Modified Example of First Embodiment [FIG. 6] : In the decorative key sheet 1, the example in which the protrusion 4a of the film sheet 4 is in close contact with the side surface of the partition groove 3a of the operation plate 3 is shown, but as shown in FIG. In addition, in the decorative key sheet 13 of the third modification, a gap t can be formed between the projection 14a of the film sheet 14 and the side surface of the partition groove 3a. In this way, since the projection 14a and the pressing operation piece 3b are separated by the gap t, the portion of the film sheet 14 corresponding to the gap t is easily bent when the pressing operation piece 3b is pressed, and the projection 14a is deformed. Can be reduced. Therefore, the load which deform | transforms the protrusion 14a becomes small, and the press load of the press operation piece 3b can be made small.

Fourth Modified Example of First Embodiment [FIG. 7] : In the decorative key sheet 1, an example in which the inside of the protrusion 4a of the film sheet 4 is a “solid part” by the protruding part 5a of the elastic sheet 5 is shown. 7, the decorative key sheet 15 of the fourth modified example can be constituted by an elastic sheet 16 having no protruding portion, and the inside of the protrusion 4a can be made hollow. In this way, since the protrusion 4a can be flexibly deformed, the load for deforming the protrusion 4a when the pressing operation piece 3b is pressed is reduced, and the pressing load of the pressing operation piece 3b can be reduced.

Fifth Modified Example of First Embodiment [FIG. 8] : The decorative key sheet 1 is provided with the elastic sheet 5, but as shown in FIG. 8, the decorative key sheet 17 of the fifth modified example is elastic. The pusher portion 18 for pressing the contact switch (not shown) can be separately formed on the back surface of the film sheet 4 without the sheet. In this way, the inside of the protrusion 4a can be made hollow as in the fourth modified example, so that the pressing load of the pressing operation piece 3b can be reduced.

6th modification of 1st Embodiment [FIG. 9] : As shown in FIG. 9, in the decoration key sheet | seat 19 of a 6th modification, the base part 20a between the press operation pieces 3b adjacent among the elastic sheets 20 is shown. A recess 20b can be provided toward the substrate outside the figure. In this way, since the thin portion is formed in the base portion 20a between the pressing operation pieces 3b, the base portion 20a can be easily deformed when the pressing operation piece 3b is pressed, and the pressing load of the pressing operation piece 3b is reduced. it can.

Seventh Modification of First Embodiment [FIG. 10] : In the decorative key sheet 1, the example in which the resin layer 7 is provided on the surface 3c on the operation surface side of the operation plate 3 is shown, but as shown in FIG. In the decorative key sheet 21 of the seventh modification, the resin layer can be eliminated, a fine uneven pattern can be formed on the outer surface of the operation plate 22 on the operation surface side, and the uneven surface portion 22a can be provided on the surface of the operation plate 22 itself. In this way, since the resin layer can be omitted, the decorative key sheet 21 can be easily manufactured, and the manufacturing cost can be reduced. Further, since the operation plate 22 is made of resin, even if the operator touches the concavo-convex surface portion 22a with his / her hand, injury can be made difficult, and the operator can safely perform an input operation. However, the material of the operation plate 22 in this case needs to make the fine unevenness pattern formed on the surface difficult to be damaged, and has the same hardness as the material used for the resin layer 7 of the decorative key sheet 1. Material is used. Formation of the concavo-convex surface portion 22a having a fine concavo-convex pattern can be performed by pressing the surface of the operation plate 22 against a mold, a metal plate, an embossing roll or the like having a fine concavo-convex pattern on the surface.

Second Embodiment [FIGS. 11 and 12] : A decorative key sheet 23 according to a second embodiment is shown in FIGS. FIG. 11 is a plan view of the decorating key sheet 23, and FIG. 12 is a cross-sectional view of the decorating key sheet 23. The decorative key sheet 23 of the second embodiment is used so as to be exposed from the operation opening 2a without a partition rail with respect to the mobile phone 2 shown in FIG. 1 like the decorative key sheet 1 of the first embodiment. .

  The decorative key sheet 23 is formed in a film shape like the base sheet 24 on the film-like base sheet 24, and is also formed in a film shape, similarly to the key top 25 serving as the operation unit of the push button switch. A frame sheet 26 as a “translucent sheet” positioned between the key tops 25, and the key top 25 and the base sheet 24, or the frame sheet 26 and the base sheet 24 are fixed by a printing adhesive layer 27. Thus, the decorative sheet 23 as a whole is formed thin. A display layer 28 for displaying symbols, numbers and the like is provided on the back surface of the key top 25.

  As shown in FIG. 12, the printing adhesive layer 27 existing between the key top 25 and the base sheet 24 is provided on the entire back surface 25d of the key top 24, and is flush with the side surface 25e of the key top 25. Is formed. On the other hand, the printing adhesive layer 27 provided between the frame sheet 26 and the base sheet 24 is not provided up to the outer edge 26 f of the frame sheet 26. Therefore, the outer edge 26f does not have the printing adhesive layer 27, and a gap is generated in which the frame sheet 26 and the base sheet 24 are not fixed. In this gap, the base sheet 24 is an unconstrained area where the frame sheet 26 is not restrained.

  The key top 25 is provided with a display layer 28 for displaying symbols, numbers, and the like on the back surface 25d thereof, and is a portion that receives a pressure of a finger or the like for an input operation of the push button switch. The key top 25 is preferably about 0.2 mm to 0.6 mm in thickness from the request for thinning the decoration key sheet 23 as a whole. Can do.

  The frame sheet 26 retains the shape of the entire decorative key sheet 23 together with the base sheet 24, prevents the key top 25 from being lifted extremely, and protects the bonded portion between the key top 25 and the base sheet 24. It is provided. A through hole 26a for exposing the key top 25 is formed from a transparent sheet-like resin film. A fine uneven pattern is formed on the surface 26b of the frame sheet 26 by the uneven surface portion 26c. As in the first embodiment, it is preferable that the interval between the concave portions in the uneven surface portion 26c is 10 μm to 500 μm, and the depth of the concave portions is 1 μm to 200 μm. More preferably, the depth of the recess is 5 μm to 100 μm. Further, a black decoration auxiliary layer 29 made of a polymer coating film is provided on the back surface 26 d of the frame sheet 26. The thickness of the frame sheet 26 is preferably about 0.2 mm to 0.5 mm from the viewpoint of harmony with the key top 25, and can be formed to be about 0.3 to 0.35 mm as one embodiment.

  In addition, when a so-called illuminated key sheet that emits light from a light source such as an LED provided inside a cellular phone to illuminate a display unit such as characters and symbols, a frame sheet (translucent resin sheet) is used. The decorative auxiliary layer on the back surface of the frame sheet can be made light-shielding so as not to cause light leakage. When a black light-blocking decorative auxiliary layer is provided on the back side of the frame sheet, it has a hairline pattern with light transmission, refraction, reflection, interference, scattering, etc., not just black due to the fine uneven pattern that is easy to see from the front side It can be a high-quality decorative key sheet.

  The base sheet 24 holds the entire shape of the decorative key sheet 23 together with the frame sheet 26, and serves as a base for placing the key top 25 and the frame sheet 26. Further, when the key top 25 is pressed, the base sheet 24 is slightly The contacts are distorted and press the contacts provided on the circuit board (not shown). The thickness of the base sheet 24 is preferably 150 μm or less, and more preferably 50 μm or less, from the request for thinning. As one embodiment, it can be formed to about 50 μm. The side surface of the base sheet 24 opposite to the surface having the key top 25 has a structure in which a bulge like a pusher is provided in a portion that presses the contact electrode according to the form of the opposing printed circuit board (not shown). You can also. When the base sheet 24 and the frame sheet 26 are compared, both can be formed of a resin film and the same material can be used, but the thickness of the base sheet 24 is preferably thinner than the frame sheet 26.

  The printing adhesive layer 27 is an adhesive layer that bonds the key top 25 and the base sheet 24, and the frame sheet 26 and the base sheet 24, and is formed by printing.

  The material of each constituent member of the decorative key sheet 23 will be described.

  The base sheet 24, key top 25, and frame sheet 26 are formed of a resin film. Examples thereof include polyethylene terephthalate resin, polybutylene terephthalate resin, polyurethane resin, polyamide resin, polypropylene resin, polystyrene resin, polycarbonate resin, polytetrafluoroethylene resin, and polyvinyl chloride resin.

  The printed adhesive layer 27 is preferably a polymer material that is softened or melted by heating to develop an adhesive force. For example, an acrylic resin, a vinyl chloride resin, a polyester resin, a urethane resin, a wax, rubber, or the like can be used. . From the viewpoint of suppressing sagging and deformation of the printing adhesive layer 27 in the bonding step by heating and pressing, it is preferable to use a type that softens rather than a type that melts by heating. In addition, the form of the ink at the time of printing has fluidity that can be printed at the time of coating, and then has the property of maintaining a solid state, such as solvent-diluted ink dissolved or dispersed in a solvent, Thus, it is possible to use an ink of a type in which a solid in a solid state is melted by heat to form a liquid. From the viewpoint of printing appropriateness such as printing accurately and delicately on a predetermined bottom surface such as the key top 25, or from the viewpoint that the solvent immediately evaporates and becomes a solid state immediately after printing and the printed shape is maintained. Is preferably used.

  An example of a method for manufacturing the decorative key sheet 23 will be described. First, the display layer 28 is printed on one side of a transparent film, and then the key top 25 is formed by punching. On the other hand, after heating and pressurizing with an embossing roll on one side of a transparent film to transfer a fine uneven pattern, the decorative auxiliary layer 29 is printed on the other side, and then the through holes 26a exposing the key tops 25 are removed by punching. A frame sheet 26 is formed. Next, the printing adhesive layer 27 is formed on the display layer 28 of the key top 25 and the decoration auxiliary layer 29 of the frame sheet 26. Finally, the printing adhesive layer 27 of the key top 25 and the frame sheet 26 is opposed to the base sheet 24, and the key top 25 and the frame sheet 26 are fixed to the base sheet 24 by heat and pressure, and the decorative key sheet 23 is attached. Obtainable. In the present embodiment, a fine uneven pattern is formed on the frame sheet 26 using an embossing roll on the sheet-like film, but a mold or a metal plate may be used instead of the embossing roll. Further, when the resin is stretched into a film, a fine uneven pattern can be formed using an embossing roll.

  The effects of the decorative key sheet 23 will be described. The decorative key sheet 23 includes a base sheet 24, a key top 25, a frame sheet 26, and a printed adhesive layer 27. In addition to being thin, the key top 25 can be pushed accurately. Since the surface 26b of the frame sheet 26 has a fine uneven pattern, the design of the fine uneven pattern can be clearly recognized. In addition, fingerprints and sebum of the operator's fingers are difficult to adhere to the uneven surface portion 26c constituting the fine uneven pattern, and deterioration in quality due to dirt can be suppressed. Furthermore, since the decoration auxiliary layer 29 that enhances the visibility of the fine uneven pattern is provided on the back surface 26d of the frame sheet 26, it is possible to prevent the decoration auxiliary layer 29 from being worn or peeled off by contact with the operator's hand. Further, since the frame sheet 26 is transparent, the color of the auxiliary decoration layer 29 on the back surface 26d can be sufficiently visually recognized through the fine concavo-convex pattern, and a high-class and innovative design can be realized.

  Since the fine concavo-convex pattern is formed on the surface 26b of the frame sheet 26 made of a film, the decorative key sheet 23 can be easily manufactured, and the manufacturing cost can be reduced.

  Since the printing adhesive layer 27 forms a side surface that is substantially flush with the side surface of the key top 25 between the base sheet 24 and the key top 25, there is no gap at the boundary between the key top 25 and the base sheet 24, The key top 25 can be firmly fixed to the base sheet 24. Therefore, it is difficult for the toe to get caught and the key top 25 can be prevented from falling off.

  Since the printing adhesive layer 27 is formed on the bottom surface of the frame sheet 26 excluding the outer edge side adjacent to the key top 25, there is a void without the printing adhesive layer 27 on the outer edge side of the frame sheet 26 with the key top 25. This portion is generated and becomes a non-restraining region when the key top 25 is pressed. Therefore, the key top 25 can be surely pushed. That is, since there is a non-constrained area around the key top 25, the base sheet 24 that supports the key top 25 has an area that is not constrained by the printing adhesive layer 27 only in the gap portion, and the base sheet 24 is easily bent. For this reason, the pressing stroke of the key top 25 can be made long, and an accurate key input operation can be performed.

First Modified Example of Second Embodiment [FIG. 13] : The decorative key sheet 23 has not been provided with a pusher, but as shown in FIG. 13, the decorative key sheet 30 of the first modified example is shown. A pusher 31 that presses a contact switch (not shown) can be separately formed on the back surface of the base sheet 24.

Second Modification of Second Embodiment [FIG. 14] : In the decorative key sheet 23, an example in which a fine uneven pattern is formed by the uneven surface portion 26c of the surface 26b of the frame sheet 26 is shown, but as shown in FIG. In the decorative key sheet 32 of the second modification, the surface 33a of the frame sheet 33 is formed flat, a resin layer 34 is provided on the surface 33a, and a fine uneven pattern is formed by the uneven surface portion 34a on the outer surface of the resin layer 34. can do.

Third Modification of Second Embodiment : In the decorative key sheet 23, an example in which a fine uneven pattern is formed by the uneven surface portion 26c of the surface 26b of the frame sheet 26 is shown, but a fine uneven pattern is formed on the surface of the key top. be able to. Moreover, a fine uneven | corrugated pattern can also be formed in the surface of both a frame sheet | seat and a key top.

Fourth Modified Example of Second Embodiment : In the decorative key sheet 23, the decoration auxiliary layer 29 is provided on the entire back surface 26d of the frame sheet 26, but a portion where the decoration auxiliary layer is not provided on the back surface 26d of the frame sheet 26 is provided. It is possible to form a portion with high visibility of the fine concavo-convex pattern and a portion that is not so.

  Finally, a modification common to the first and second embodiments will be described.

First Modified Example Common to Each Embodiment [FIG. 15] : As shown in FIG. 15A, the uneven surface portions 7a, 22a, 26c, and 34a are composed of concave and convex portions having a rectangular cross section. However, in the first modification, it may be configured with a V-shaped cross section or a U-shaped cross section as shown in FIG. Further, as shown in FIG. 15C, it may be configured in an irregular shape.

Second Modification Common to Each Embodiment : A protective layer may be provided on the upper surfaces of the uneven surface portions 7a, 22a, 26c, and 34a. In this way, the uneven surface portions 7a, 22a, 26c, and 34a are not easily damaged, and the design quality can be maintained. Such a protective layer does not fill the unevenness of the fine uneven pattern, and is preferably provided so as to follow the surface shape of the fine uneven pattern.

Third modification common to each embodiment (FIG. 16) : In addition to the fine uneven pattern by the uneven surface portions 7a, 22a, 26c, 34a, on the back side of the operation plate or the frame sheet as a "translucent sheet" A fine uneven pattern can be formed by the uneven surface portion. In this way, as shown in FIG. 16, for example, a linear hairline pattern can be crossed three-dimensionally, and a novel design can be realized.

Fourth Modification Common to Each Embodiment [FIGS. 17 and 18] : The fine uneven pattern is exemplified by the linear hairline pattern as described above, but the circular ripple pattern as shown in FIG. It is also possible to provide an elliptical ripple as shown in FIG. 4 on a part of the operation plate or the frame sheet as the “translucent sheet”.

  The decorative key sheet (23) shown in the second embodiment and a decorative key sheet of a comparative example having a fine uneven pattern on the back surface of the frame sheet with respect to the decorative key sheet (23) were manufactured. First, a resin film made of polycarbonate resin having a thickness of 300 μm was provided with a fine concavo-convex pattern having a recess interval of 200 μm and a recess depth of 50 μm through an embossing roll. A frame sheet I having a decoration auxiliary layer (29) having a thickness of 100 nm deposited on the surface opposite to the textured surface having the fine concavo-convex pattern, and a decoration having a thickness of 100 nm deposited on the rugged surface. A frame sheet II on which an auxiliary layer was formed was produced. On the other hand, on a base sheet (24) made of a polyurethane resin having a thickness of 50 μm, a key top made of a polycarbonate resin having a thickness of 400 μm is formed via a printing adhesive layer (27) made of polyurethane resin having a thickness of 10 μm ( 25) and the previous frame sheet I or frame sheet II were placed and fixed. At this time, the frame sheet I was fixed so that the uneven surface portion appeared on the surface, and the uneven surface portion of the frame sheet II was fixed to the printing adhesive layer. Thus, the decorative key sheet (23) of the present invention including the frame sheet I and the decorative key sheet of the comparative example including the frame sheet II were obtained.

  When the obtained decorative key sheet (23) and the decorative key sheet of the comparative example were placed on a desk and asked for opinions on the surface state of each decorative key sheet by five different persons, four persons of the present invention The decorative key sheet (23) pointed out that the fine concavo-convex pattern was clearly visible, and the remaining one pointed out that the decorative key sheet of the comparative example clearly showed the fine concavo-convex pattern.

The external view of a mobile telephone provided with the decorating key sheet for pushbutton switches of this invention. The top view of the decorating key sheet for pushbutton switches of 1st Embodiment. FIG. 3 is a sectional view taken along line SA-SA in FIG. 2. Sectional drawing equivalent to FIG. 3 of the decorating key sheet | seat for pushbutton switches by the 1st modification of 1st Embodiment. Sectional drawing equivalent to FIG. 3 of the decorating key sheet | seat for pushbutton switches by the 2nd modification of 1st Embodiment. Sectional drawing equivalent to area | region R2 in FIG. 3 of the decoration key sheet | seat for pushbutton switches by the 3rd modification of 1st Embodiment. Sectional drawing equivalent to the area | region R2 in FIG. 3 of the decorating key sheet for pushbutton switches by the 4th modification of 1st Embodiment. Sectional drawing equivalent to FIG. 3 of the decorating key sheet | seat for pushbutton switches by the 5th modification of 1st Embodiment. Sectional drawing equivalent to area | region R2 in FIG. 3 of the decoration key sheet | seat for pushbutton switches by the 6th modification of 1st Embodiment. Sectional drawing equivalent to FIG. 3 of the decorating key sheet | seat for pushbutton switches by the 7th modification of 1st Embodiment. The top view of the decorating key sheet | seat for pushbutton switches of 2nd Embodiment. SB-SB sectional view taken on the line of FIG. Sectional drawing equivalent to FIG. 12 of the decorating key sheet for pushbutton switches by the 1st modification of 2nd Embodiment. Sectional drawing equivalent to FIG. 12 of the decorating key sheet | seat for pushbutton switches by the 2nd modification of 2nd Embodiment. The schematic cross section of the modification of the fine concavo-convex pattern common to each embodiment. The top view of the decorating key sheet | seat for pushbutton switches of this invention which shows a linear hairline crossing pattern. The top view of the decorating key sheet | seat for pushbutton switches of this invention which shows a circular ripple pattern. The top view of the decorating key sheet | seat for pushbutton switches of this invention which shows an elliptical ripple pattern.

Explanation of symbols

1 decorative key sheet for pushbutton switches (first embodiment)
2 mobile phone 2a operation opening 3 operation plate 3a partition groove 3b pressing operation piece 3c front surface 3d back surface 4 film sheet 4a protrusion 5 elastic sheet 5a protruding portion 5b base portion 5c pusher portion 6 display portion 7 transparent resin layer 7a uneven surface portion 8 light Reflective layer 9 Decorative key sheet for pushbutton switches (first modification of the first embodiment)
DESCRIPTION OF SYMBOLS 10 Operation board 10a Concave part 11 Decorative key sheet | seat for pushbutton switches (2nd modification of 1st Embodiment)
12 film sheet 12a protrusion 13 decorative key sheet for pushbutton switch (third modification of the first embodiment)
14 Film sheet 14a Protrusion 15 Decorative key sheet for push button switch (fourth modification of the first embodiment)
16 Elastic Sheet 17 Decorative Key Sheet for Pushbutton Switch (Fifth Modification of First Embodiment)
18 Pusher 19 Decorative Key Sheet for Pushbutton Switch (Sixth Modification of First Embodiment)
DESCRIPTION OF SYMBOLS 20 Elastic sheet 20a Base part 20b Recessed part 21 Decorative key sheet for pushbutton switches (seventh modified example of the first embodiment)
22 operation plate 22a uneven surface portion 23 decorative key sheet for push button switch (second embodiment)
24 base sheet 25 key top 25d back surface 25e side surface 26 frame sheet 26a through hole 26b surface 26c uneven surface portion 26d back surface 26f outer edge 27 printing adhesive layer 28 display layer 29 decoration auxiliary layer 30 decorative key sheet for push button switch (of the second embodiment) First modification)
31 Pusher 32 Decorative Key Sheet for Pushbutton Switch (Second Modification of Second Embodiment)
33 Frame sheet 34 Resin layer 34a Uneven surface portion t Clearance

Claims (12)

It has a key top and a base sheet made of a resin film,
The translucent sheet is a frame sheet arranged on the base sheet side by side with the key top,
It is formed as a printing layer, and includes a printing adhesive layer made of a cured body that is in contact with the key top, frame sheet, or base sheet in a softened or molten state,
A decorative key for a pushbutton switch having a fine concavo-convex pattern on the operation surface side of the translucent sheet and having a decorative auxiliary layer on the side opposite to the operation surface of the translucent sheet to enhance the visibility of the fine concavo-convex pattern Sheet.   The decorative key sheet for a pushbutton switch according to claim 1, wherein the outer surface on the operation surface side of the translucent sheet has a fine uneven pattern. The decorative key sheet for a pushbutton switch according to claim 1 or 2 , further comprising: a translucent resin layer on a surface on an operation surface side of the translucent sheet, and the fine uneven pattern on the outer surface of the resin layer. The decorative key sheet for pushbutton switches according to any one of claims 1 to 3, wherein the surface of the key top has the fine uneven pattern. The decorative key sheet for a pushbutton switch according to any one of claims 1 to 4, wherein the decoration auxiliary layer is a light reflecting layer having a metallic luster. The translucent sheet is an operation plate provided with a partition groove that forms a pressing operation piece that can be pressed and displaced, and provided with a protrusion that bulges toward the partition groove from the side opposite to the operation surface of the operation plate. The decorative key sheet for pushbutton switches according to any one of claims 1 to 5, further comprising a film sheet. The decorative key sheet for a pushbutton switch according to claim 6, wherein the protrusion protrudes from the outer surface of the operation plate. The decorative key sheet for a pushbutton switch according to claim 6 or 7 , further comprising an elastic sheet made of a rubber-like elastic body on the back surface of the film sheet. The decorative key sheet for a pushbutton switch according to any one of claims 6 to 8 , wherein the inside of the protrusion is a solid part made of a rubber-like elastic body. The decorative key sheet for a pushbutton switch according to any one of claims 6 to 9, further comprising a pressing operation piece partitioned by an annular partition groove.   The decorative key sheet for a pushbutton switch according to claim 10, wherein the printed adhesive layer forms a side surface substantially flush with a side surface of the key top between the base sheet and the key top.   The decorative key sheet for a pushbutton switch according to claim 10 or 11, wherein the printing adhesive layer is formed on the bottom surface of the frame sheet excluding the outer edge side adjacent to the key top.

Images